Aviator 902S

I have an '85 GSL 12A, and a few months ago I swapped in a used starter to replace the one that had gotten to the point where it only ground the teeth off.

Having replaced many 1st gen starters on my three previous 1st gens (all '81 or '82, and all with 5-spd std) The first thing I noticed this time was that:

a) The starter pulled out of this '85 (5-spd std) had a larger diameter drive gear with 12 teeth on it, and only appeared to be engaged with the flywheel by a distance of about 1/8" judging by the wear patterns (vs. over 1/4" engagement with the 8-tooth unit it was to replace). Still, it was in the car when I bought it and had run for at least a year or two in that car.

b) The replacement starter (from a junkyard '82 5-spd) had a smaller diameter drive gear with only 8 teeth. It also appeared to be a rebuilt unit considering the very good conditiojn it was in. It worked fine with no adverse noise until a couple days ago, after I attempted to have the car jump-started (un-successfully after about two 45-second attempts at -20F) and only succeeded in burning it out. This one failed the bench test and would occasionally engage if I manually rotated the stater to it's one remaining "sweet spot."

I found a replacement that passed the bench test but has the larger gear with 12 teeth. The teeth didn't look to be in the best of shape, but no as bad as some that I'd seen.

My question is, did Mazda make a different starter for automatic RX7s than for standards and if so, is this 12-tooth gear one it? Or did Mazda have the 12-tooth one only in '84 -85 1st gens?

I'm about to start calling rebuilt starter supply shops as soon as they open for business and I'm not sure I can count on them to give me the right starter if one of these really is not compatible. Any info very much appreciated.

Brett.

Gregs

just upgrade to an fc starter...

-greg

Rx7carl

The auto did use a different starter. But its totally different than what you have. The auto starter has planetary gearing and no nose piece on it.

Aviator 902S

If all FC starters are of the same dimensions as the one I saw last night (from a T-II) they won't work on a first gen.

hornbm

TII starters are different from the N/A FC starters due to the larger flywheel.

I have a FC starter on my car and it works great. Sounds alot different than first gen starters too

Aviator 902S

Thanks Carl. I found that out about the starter used in automatics from one of the rebuilders, who confirmed that those ones are geared.

What I've discovered about the two starters in question is this:

The one with the smaller 8-tooth gear was used up to VIN 622565 inclusive, which I believe was '83. All subsequent 1st gens, including the GSL-SE, used the starter with the larger 11-tooth drive gear.

However, I don't know the history of the car I own. It's an '85 GSL 12A but if the flywheel was swapped (or the transmission, or the engine) it may be now set up for the older 8-tooth starter.

Since the starter that came with this car when I bought it was the 11-tooth one and never did fully engage before crapping out, and since the 8-tooth unit worked fine until I fried it while the most recent 11-tooth one failed to engage, I've decided to stick with the tried and true. The shop is overhauling the 8-tooth starter for me as I sit here. I'll report back in a few hours after I've re-installed it.

hornbm

I really doubt the flywheel was swapped if its still a stock flywheel. The flywheels have a built in counterweight that are specific to the years if the actual rotors used in your engine. Because you have an 85 engine, im assuming its the origional with rotors from an 85 (rotors earlier than 84 were heavier) so if you had a flywheel from like 83 or something, im sure you would notice some really really bad vibration from the engine.

If your engine is from an 85, you have the 85 flywheel, you can be sure of it

Rx7carl

No problem, and what I discovered is that they are $150 at Autozone.

Gregs

turbo starters arent the same dimensions as n/a ones , i have an n/a starter on my gsl-se and had one on my old 81....

Aviator 902S

That's what I was told just a few hours ago. Nice to know for future ref.

Aviator 902S

So it looks like at some point an '83 or prior engine was installed in this car, since the older style starter fits and works just fine. Here's the update:

I decided to have the shop rebuild my starter, the one from the '82. This seemed like the safest bet because it worked fine previously while the later style did not. Sold them the newer style starter for $10 (it wasn't in the best of shape even though it passed the bench test) and once that was deducted from the cost of the rebuild I ended up spending $90 including tax.

But there was a snag--- they replaced the armature, which allowed the starter to pass their bench test. At least it seemed to. When I installed it I got the slightest click and nothing more. Since the other starter kicked in and spun (albiet, without engaging) I knew it had nothing to do with my wiring. I took it back and exchanged for another. While there we discovered that the solenoid on the first one was also toast. This time I watched them bench test the second exchange. It passed, I installed it and it fired up with no complaints. Problem solved and lesson learned.

Thanks for all the help guys. Hopefully I won't have to crawl under this beast again any time soon.